scholarly journals Robust UV-Curable Antimicrobial Polymeric Coatings for Medical Plastics Prepared by Controlled Radical Polymerization

2021 ◽  
Author(s):  
Rachel L. Shum
Keyword(s):  
Radical Polymerization ◽  
Active Sites ◽  
Antimicrobial Properties ◽  
Polymeric Coatings ◽  
Gram Positive ◽  
Uv Curable ◽  
Antimicrobial Coatings ◽  
Polymeric Thin Films ◽  
Potential Applications ◽  
Hospital Acquired

In response to hospital acquired infections stemming from biofilms and the impending antibiotic resistance crisis, the development of non-traditional, non-leachable antimicrobials have gained significant traction. Contact-active antimicrobial coatings physically attached to surfaces with cationic active sites, such as ammonium and phosphonium, are of particular interest in the prevention of pathogenic bacterial transfer. Previously reported antimicrobial coatings are found to be susceptible to abrasion, significantly limiting their potential applications. In this work, a range of robust, antimicrobial polymeric coatings synthesized by control radical polymerization are presented. Polymeric thin film coatings possessing cationic groups with n-alkyl substituents of n ≤ 4 demonstrated antimicrobial properties against gram-positive bacteria, while species containing bulkier substituents were biologically inactive, contradictory of previously reported monomeric coatings. Cationic polymeric brush coatings were found to have a higher antibacterial activity against the gram-positive model compared to its non-brush equivalent, but failed against the gram-negative model. These polymeric thin films demonstrate the complexity of antimicrobial coating designs and facilitates the investigation into the architecture of these coatings.

scholarly journals Robust UV-Curable Antimicrobial Polymeric Coatings for Medical Plastics Prepared by Controlled Radical Polymerization

2021 ◽  
Author(s):  
Rachel L. Shum
Keyword(s):  
Radical Polymerization ◽  
Active Sites ◽  
Antimicrobial Properties ◽  
Polymeric Coatings ◽  
Gram Positive ◽  
Uv Curable ◽  
Antimicrobial Coatings ◽  
Polymeric Thin Films ◽  
Potential Applications ◽  
Hospital Acquired

In response to hospital acquired infections stemming from biofilms and the impending antibiotic resistance crisis, the development of non-traditional, non-leachable antimicrobials have gained significant traction. Contact-active antimicrobial coatings physically attached to surfaces with cationic active sites, such as ammonium and phosphonium, are of particular interest in the prevention of pathogenic bacterial transfer. Previously reported antimicrobial coatings are found to be susceptible to abrasion, significantly limiting their potential applications. In this work, a range of robust, antimicrobial polymeric coatings synthesized by control radical polymerization are presented. Polymeric thin film coatings possessing cationic groups with n-alkyl substituents of n ≤ 4 demonstrated antimicrobial properties against gram-positive bacteria, while species containing bulkier substituents were biologically inactive, contradictory of previously reported monomeric coatings. Cationic polymeric brush coatings were found to have a higher antibacterial activity against the gram-positive model compared to its non-brush equivalent, but failed against the gram-negative model. These polymeric thin films demonstrate the complexity of antimicrobial coating designs and facilitates the investigation into the architecture of these coatings.

scholarly journals Antimicrobial Properties of MX-2401, an Expanded-Spectrum Lipopeptide Active in the Presence of Lung Surfactant

2011 ◽  
Vol 55 (8) ◽  
pp. 3720-3728 ◽  
Author(s):  
Dominique Dugourd ◽  
Haiyan Yang ◽  
Melissa Elliott ◽  
Raymond Siu ◽  
Jacob J. Clement ◽  
...  
Keyword(s):  
Lung Surfactant ◽  
Antimicrobial Properties ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Lipopeptide Antibiotic ◽  
Hospital Acquired

ABSTRACTMX-2401 is an expanded-spectrum lipopeptide antibiotic selective for Gram-positive bacteria that is a semisynthetic analog of the naturally occurring lipopeptide amphomycin. It was active againstEnterococcusspp., including vancomycin-sensitiveEnterococcus(VSE),vanA-,vanB-, andvanC-positive vancomycin-resistantEnterococcus(VRE), linezolid- and quinupristin-dalfopristin-resistant isolates (MIC90of 4 μg/ml), methicillin-resistantStaphylococcus aureus(MRSA) and methicillin-sensitiveS. aureus(MSSA) (MIC90of 2 μg/ml), coagulase-negative staphylococci, including methicillin-sensitiveStaphylococcus epidermidis(MSSE) and methicillin-resistantS. epidermidis(MRSE) (MIC90of 2 μg/ml), andStreptococcusspp. including viridans group streptococci, and penicillin-resistant, penicillin-sensitive, penicillin-intermediate and macrolide-resistant isolates ofStreptococcus pneumoniae(MIC90of 2 μg/ml). MX-2401 demonstrated a dose-dependent postantibiotic effect varying from 1.5 to 2.4 h. Furthermore, MX-2401 was rapidly bactericidal at 4 times the MIC againstS. aureusandEnterococcus faecalis, with more than 99.9% reduction in viable bacterial attained at 4 and 24 h, respectively. The MICs of MX-2401 against MRSA, MSSA, VSE, and VRE strains serially exposed for 15 passages to sub- to supra-MICs of MX-2401 remained within three dilutions of the original MIC. In contrast to that of the lipopeptide daptomycin, the antibacterial activity of MX-2401 was not affectedin vitroby the presence of lung surfactant, and MX-2401 was activein vivoin the bronchial-alveolar pneumonia mouse model, in which daptomycin failed to show any activity. Moreover, the activity of MX-2401 was not as strongly dependent on the Ca2+concentration as is the activity of daptomycin. In conclusion, MX-2401 is a promising new-generation lipopeptide for the treatment of serious infections with Gram-positive bacteria, including hospital-acquired pneumonia.

scholarly journals A Phase 3, Randomized, Double-Blind Study Comparing Tedizolid Phosphate and Linezolid for Treatment of Ventilated Gram-Positive Hospital-Acquired or Ventilator-Associated Bacterial Pneumonia

2021 ◽  
Author(s):  
Richard G Wunderink ◽  
Antoine Roquilly ◽  
Martin Croce ◽  
Daniel Rodriguez Gonzalez ◽  
Satoshi Fujimi ◽  
...  
Keyword(s):  
Clinical Response ◽  
Bacterial Pneumonia ◽  
Double Blind Study ◽  
Phase 3 ◽  
Gram Positive ◽  
Double Blind ◽  
Intention To Treat ◽  
The Difference ◽  
Hospital Acquired ◽  
Noninferiority Margin

Abstract Background Hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP) are associated with high mortality rates. We evaluated the efficacy and safety of tedizolid (administered as tedizolid phosphate) for treatment of gram-positive ventilated HABP/VABP. Methods In this randomized, noninferiority, double-blind, double-dummy, global phase 3 trial, patients were randomized 1:1 to receive intravenous tedizolid phosphate 200 mg once daily for 7 days or intravenous linezolid 600 mg every 12 hours for 10 days. Treatment was 14 days in patients with concurrent gram-positive bacteremia. The primary efficacy end points were day 28 all-cause mortality (ACM; noninferiority margin, 10%) and investigator-assessed clinical response at test of cure (TOC; noninferiority margin, 12.5%) in the intention-to-treat population. Results Overall, 726 patients were randomized (tedizolid, n = 366; linezolid, n = 360). Baseline characteristics, including incidence of methicillin-resistant Staphylococcus aureus (31.3% overall), were well balanced. Tedizolid was noninferior to linezolid for day 28 ACM rate: 28.1% and 26.4%, respectively (difference, –1.8%; 95% confidence interval [CI]: –8.2 to 4.7). Noninferiority of tedizolid was not demonstrated for investigator-assessed clinical cure at TOC (tedizolid, 56.3% vs linezolid, 63.9%; difference, –7.6%; 97.5% CI: –15.7 to 0.5). In post hoc analyses, no single factor accounted for the difference in clinical response between treatment groups. Drug-related adverse events occurred in 8.1% and 11.9% of patients who received tedizolid and linezolid, respectively. Conclusions Tedizolid was noninferior to linezolid for day 28 ACM in the treatment of gram-positive ventilated HABP/VABP. Noninferiority of tedizolid for investigator-assessed clinical response at TOC was not demonstrated. Both drugs were well tolerated. Clinical Trials Registration NCT02019420.

scholarly journals Silver-Derived Antimicrobial Coatings for the Prevention of Microbial Biofilms in Metal Pipes

2021 ◽  
Vol 232 (8) ◽  
Author(s):  
M. Vela-Cano ◽  
C. Garcia-Fontana ◽  
F. Osorio ◽  
A. González-Martinez ◽  
J. González-López
Keyword(s):  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Pilot Scale ◽  
Biological Factors ◽  
Antimicrobial Coatings ◽  
Microbial Biofilms ◽  
Physical Chemical ◽  
Silver Zeolite ◽  
Metal Pipes ◽  
Pipeline Corrosion

AbstractBiodeterioration is one of the most important processes in metal pipeline corrosion, and it can be due to physical, chemical, and biological factors. Coatings rich in silver have been used to inhibit this undesirable phenomenon. In this study, the antimicrobial properties of several silver-containing products used as a coating in pipelines were determined on a pilot scale in order to evaluate the ability of silver to inhibit biofilm formation. The results showed that the coating with silver zeolite at a concentration of 2000 mg L–1 inhibited the formation of a microbial biofilm and prevented the biodeterioration process. Therefore, from our study, it can be concluded that silver zeolite shows greater protection capacity than other silver preparations and presents advantages in relation to other silver coatings that are currently available

scholarly journals Preparation and Characterization of a Novel Terbium Complex Coordinated with 10-Undecenoic Acid for UV-Cured Coatings

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Chenjie Jiao ◽  
Rong Zhong ◽  
Yanfang Zhou ◽  
Hongfei Zhang
Keyword(s):  
Rare Earth ◽  
Green Light ◽  
Precipitation Method ◽  
Rare Earth Complex ◽  
Terbium Complex ◽  
Uv Curable ◽  
Good Thermal Stability ◽  
Potential Applications ◽  
Undecenoic Acid ◽  
The Rare Earth

A UV-cured composite containing a rare earth complex was prepared for this study. First, the photoluminescent terbium complex was synthesized with a long-chain unsaturated fatty acid (10-Undecenoic acid) by a solution precipitation method, resulting in the 10-UA-Tb(III) complex. Its structure was proven by FTIR, elemental analysis, XRD, and TGA. The results indicated that the organic acid ligand successfully coordinated with the Tb3+ ion and that the complex had a chelate bidentate structure. The emission spectrum of the 10-UA-Tb(III) complex indicated that the complex can emit a bright green light with the unique luminescence of the Tb3+ ion. Furthermore, the luminescence properties of complexes with different ratios of Tb3+ and ligand were studied, and the ratio of Tb3+ and the ligand had an obvious impact on the luminescence intensity of the 10-UA-Tb(III) complex. Subsequently, the prepared rare earth complex was doped into a UV-cured coating in different proportions to obtain a UV-cured composite. The morphology of the rare earth UV-cured composite was observed by SEM. The images showed that the rare earth complex was dispersed uniformly in the polymer matrix. Moreover, the composites could emit fluorescence. Additionally, it has good thermal stability and compatibility with the resin. Therefore, these composites should have potential applications in UV curable materials, such as luminescence coatings.

Preparation of Anion Exchange Membranes Base on Fluoro-Polyacrylate for Alkaline Fuel Cells

2012 ◽  
Vol 485 ◽  
pp. 84-87
Author(s):  
Jun Fang ◽  
Yong Bin Wu ◽  
Yan Mei Zhang
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Radical Polymerization ◽  
Anion Exchange ◽  
Butyl Methacrylate ◽  
Anion Exchange Membranes ◽  
Reaction Conditions ◽  
Alkaline Fuel Cells ◽  
Fuel Cell Application ◽  
Potential Applications

A series of hydroxyl conducting anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate and fluoro-polyacrylate were prepared by radical polymerization, quaternization and alkalization. The reaction conditions of polymerization were discussed and the potential applications of the resulting membranes in alkaline fuel cells were assessed. The results show that the membranes have adequate conductivity for fuel cell application.

Radical polymerization of acrylate copolymer-based GMA for use as a UV-curable layer via thin coating

2011 ◽  
Vol 31 (4) ◽  
pp. 271-279 ◽  
Author(s):  
Sungchul Hong ◽  
Jihye Kim ◽  
Moon-Sun Kim ◽  
Byung-Woo Kim
Keyword(s):  
Radical Polymerization ◽  
Thin Coating ◽  
Uv Curable ◽  
Acrylate Copolymer

scholarly journals Biogenic Silver Nanoparticles Conjugated with Nisin: Improving the Antimicrobial and Antibiofilm Properties of Nanomaterials

Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1271-1285
Author(s):  
Patricia Zimet ◽  
Ruby Valadez ◽  
Sofía Raffaelli ◽  
María Belén Estevez ◽  
Helena Pardo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Value Added ◽  
Green Technology ◽  
Natural Food ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Biogenic Silver Nanoparticles

Microbial technology offers a green alternative for the synthesis of value-added nanomaterials. In particular, fungal compounds can improve silver nanoparticle production, stabilizing colloidal nanoparticles. Based on a previous study by our group, silver nanoparticles obtained using the extracellular cell-free extracts of Phanerochaete chrysosporium (PchNPs) have shown antimicrobial and antibiofilm activity against Gram-negative bacteria. Moreover, nisin—a bacteriocin widely used as a natural food preservative—has recently gained much attention due its antimicrobial action against Gram-positive bacteria in biomedical applications. Therefore, the aim of this work was to conjugate biogenic silver nanoparticles (PchNPs) with nisin to obtain nanoconjugates (PchNPs@nis) with enhanced antimicrobial properties. Characterization assays were conducted to determine physicochemical properties of PchNPs@nis, and also their antibacterial and antibiofilm activities were studied. The formation of PchNPs@nis was confirmed by UV-Vis, TEM, and Raman spectroscopy analysis. Different PchNPs@nis nanobioconjugates showed diameter values in the range of 60–130 nm by DLS and surface charge values between −20 and −13 mV. Nisin showed an excellent affinity to PchNPs, with binding efficiencies higher than 75%. Stable synthesized PchNPs@nis nanobioconjugates were not only able to inhibit biofilm formation by S. aureus, but also showed inhibition of the planktonic cell growth of Staphyloccocus aureus and Escherichia coli, broadening the spectrum of action of the unconjugated antimicrobials against Gram-positive and Gram-negative bacteria. In conclusion, these results show the promising application of PchNPs@nis, prepared via green technology, as potential antimicrobial nanomaterials.

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